1. Field of the Invention
The present invention relates to an optical disk device, more particularly to a heat dissipation structure thereof.
2. Description of the Related Art
In recent years, the amount of heat generated from a device drive LSI, disk rotation motor, optical head moving motor, optical head and the like has increased accompanied by demands for intensified recording density in the optical disk device, improvement of rotation speed and access velocity and the like. As a consequence, the temperature inside the disk device rises, so that its respective devices and components sometimes may exceed a limit temperature.
To avoid the temperature rise in the optical disk device, conventionally, air is taken compulsorily from outside of the device with a cooling fan so as to cool the inside of the drive unit and discharge out air having a raised temperature.
Japanese Patent Application Laid-Open No. 2001-319469 has described a structure for cooling air in the disk device with a Peltier element and blowing cooled air to an optical head with a fan. However, the Peltier element or fan has a problem that they need power and the fan produces noise.
Contrary to this, there is available a method for cooling air inside the drive unit using air flow induced by disk rotation without provision of any cooling fan. Japanese Patent Application Laid-Open No. 2003-151259 has described a structure in which cool air outside is sucked in through an assembled portion of the optical disk device and after it cools the optical head and circuit board, the air is discharged through an opening portion provided in a face opposing a front panel with flow induced by disk rotation.
Therefore, technology for dissipating heat generated inside the optical disk device without outside air is demanded. Japanese Patent Application Laid-Open No. 2004-310883 has described a structure in which a tray for carrying a disk has a through portion provided between a disk side area and an area opposing the disk and air flow induced by disk rotation is used for cooling the optical head and board.
[Patent document 1]: Japanese Patent Application Laid-Open No. 2001-319469
[Patent document 2]: Japanese Patent Application Laid-Open No. 2003-151259
[Patent document 3]: Japanese Patent Application Laid-Open No. 2004-310883
According to the technology described in the Japanese Patent Application Laid-Open No. 2004-310883, the tray portion is provided with a through portion. However, the through portion has a right or nearly right angle with respect to a rotation flow produced tangential to the disk by a disk rotation and thus, air flow to the optical head and board may weaken.